Figured I'd share this one with everyone. I'm running a built 2.0L block (crower rods, ross pistons, no balance shafts) with a bunch of goodies on it and I've been having a lot of problems with what I've determined to be phantom knock. Here is a snapshot of two dyno runs. One clean, the other with approximately 14 counts of knock in the 3500 rpm range. Anytime a run is performed from low RPM, the ECU will pick up the extra noise from the block and determine that it is knock - always in the 2500 - 3800 RPM range. Note how we started the pull on the clean run from about 3600 RPM...

I'm pretty tired of having to deal with this, so I've started adjusting the knock filters to help out,

... to be continued ...

l8r)

 

knock might be cause because you dont have balance shaft in your engine

 

Yep, I'm pretty sure the phantom knock is being caused by a combination of no balance shafts and upgraded engine internals. Just amazes me to see how much of an impact the ECU can have when it squashes timing and adds fuel though...

l8r)

 

that's a good thing and a security blanket when the knock is real!

 

thats why a lot of tuners use standalones when the engine has been heavily modified you should get an aem standalone and have a tune from david bushur

 

^ As soon as you send me a check for $3000.

Personally I think it's entirely possible to tune around the phantom knock with the stock ECU. Now that I have all of the other annoying bugs worked out of the car, I will start concentrating on the knock issues...

l8r)

 

Sounds like a bang.........

 

Every time I accelerate from 2000rpm with less than half throttle I get counts that climb upwards until I either give more throttle or lift. Thats with stock engine, balancers and whatnot.

The car knocked it's way from the factory to me when I bought it.

 

$3000 i never thought it was that expensive
i hope you resolve your issues with that knock
good luck and please keep us updated